Older vehicles & B99

Want to run B99 in an older vehicle?

If you are driving a pre-1990 vehicle, or have over 100,000 miles on your engine, we’ve prepared a checklist to ensure your adoption of B99 (99% biodiesel) is informed and hitch-free.

As one of the premier providers of biodiesel in the U.S., Propel has learned a lot about what it takes to switch to and drive with biodiesel. By sharing our knowledge, we hope to offer you assistance when looking to set up your car, find support, compare quality standards, decipher warranty information and communicate with mechanics.

Our Community grows with every fill.
Hear our customers' Fuel Good Stories.

Step 1: Prepare Your Vehicle

If you drive a pre-1990 vehicle with a diesel engine, we suggest you update your hoses and gaskets from the original rubber to Viton®. Biodiesel is a natural cleaning agent, and running a very high blend, such as B99, will slowly degrade any natural or nylon hose or gasket.

Many less-informed mechanics, car dealers and fuel station owners don’t know much about biodiesel, yet. As an early-adopter, it is important to connect with knowledgeable service and support. Just locate and screen your local diesel mechanics and only choose those familiar with the benefits and nuances of biodiesel.

Step 2: Make the Switch

To make a smooth transition from diesel to biodiesel, we suggest gradually increasing your biodiesel ratios over time.

Because biodiesel acts as a natural cleaning agent, it will break down the sludge and sediment in your fuel tank left behind by petroleum diesel. The higher the miles on your car, the more likely you will have heavy sludge build-up. By gradually increasing biodiesel ratios, the sludge will slowly be cleared away.

We suggest this recipe for the smoothest transition:

Two sequential tanks of B20 *
Two sequential tanks of B50
One tank of B99 or B100
Replacing your fuel filter

A more immediate switch to B99 or B100 could cause a plugged fuel filter.

Step 3: Maintain your Ride

For ongoing maintenance and service, we suggest proactive use of additives and continued use of quality biodiesel supported by reputable manufacturers and retailers.

Propel sells only the highest quality-certified biodiesel. Make sure to ask where your biodiesel originates before buying from any biodiesel retailer.

Experienced high-blend biodiesel drivers follow these best practices. We recommend you do, too:

Switch your fuel filter about every 10,000 miles.
Keep a spare fuel filter in your vehicle in case your filter clogs.
Fuel additives may help your diesel engine run more efficiently. Diesel Kleen and Power Service Diesel 911 promise to remove water from fuel system and extend the life of fuel-filters, fuel injection pumps and fuel injectors.